Improvement in corrugating sheet metal



WORTHEN 6L RENWICK.

l Corrugaltng Sheet Metal. No. 24,689. Patented July 5, `1859.

UNITED `STATES PATENT OFFICE. f

WILLIAM E. VVORTHEN AND HENRY B. RENWIOK, OF NENV YORK, N. Y.

IMPROVEMENT IN CORRUGATING SHEET METAL.

Specification forming part of Letters Patent No. 24,689, dated Jujy 5, 1859.

To @ZZ whom it may concern:

Be itknown that we, WILLIAM E. WORTHEN and HENRY B. RENWICK, civil and mechanical engineers, and both of the city, county, and State of New York, have discovered a certain new and useful Method of Corrugating Sheet Metal, or of molding it into conformations similar in their nature to corrugations; and we do hereby declare that the following speciication, taken in connection with the drawings, is a full, clear, and exact description thereof.

In the drawings, Figures 1, 2, and Sare sec tions of pairs of dies with sheet metal between them, representing the plans by which sheet metal is corrugated or attempted to be corrugated by methods now in use, Fig. 2 being a section through dies substantiallysu'ch as are now in use for eorrugating metallic'boats. Figs. 4, 5, and 6 are sections th rough dies representing the mannerin which pieces or sheets of metal are to be corrugated by the method vdevised by us; and Fig. 7 is a perspective drawing ofa machine by means of which our Vmethod has been successfully applied in practice.

Corrugated or molded sheet Vmetal is now extensively used for floors, partitions, beams, cornices, and gutters of buildings, or for similar articles; also, for boats, small vessels, and a great variety of other uses; but its general employment is hindered by the expense and difficulty of corrugating it, according to the methods nowin use. These are three, chiefly: First, by means of hammers and sets, which are applied chiefly to corrugating floors, partitions, and similar articles; second, by similar means applied to sections of different moldings-such as cornices-which are afterward brazed or otherwise attached to each other so as to make up a whole; and, thirdly, by means of properly-shaped male and female dies extending over the sheet or sheets to be corrugated or molded, and between which the sheet is placed. These dies are then caused to approach the one to the other generally by means of powerful hydrostatic presses, and the` metal usually conforms itself to the desired shape. The two first are essentially hand processes, while the third is a mechanical method, and our invention is an improvement upon it. In this process as now practiced the upper die approaches the lower one, acting upon the metal between them, and commences to form it with great ease and small expenditure of power until the corners of the die, if there be corners, or certain salient parts, begin to nip the sheet, as ata a a. As the met-al approaches .nearer to its ultimate shape it must creep in toward the center of the die, in order to supply sufiiclient surface to conform to the curves and angles of the mold, and this creeping must take place not only under the resistance due to the friction of the bent metal sliding over the curves of the dies, but the creeping is further resisted by the force required to bend the metal out of the shapeit has already taken and into the shape of the next succeeding corrugation. As the dies continue to approach, making the bends shorter and the nips tighter, the power required becomes enormous, and the friction is so great that the sheet usually ceases to creep and actually stretches in its efforts to afford sufficient surface. This stretching takes place in actual practice even in corrugatiug the sides of small boats, where the metal is not thick and the corrugations are shallow. lf the sheet be highly ductile, it does not tear, but is only weakened and ren` dered brittle; but it often happens that the sheets rend apart in several places, thus not only losing the labor expended, but destroying the sheet itself. The difficulties thus set forth are so great that it is not attempted to corrugate metal deeply by this process, and resort is had to hand hammers and sets. Now, our invention, as is proved by actual practice on an experimental machine, remedies the evil completely, lessens the power required very materially, does not render the sheet brittle to any practical extent, entirely pre vents fracture, and by its use we are enabled to corrugate moldings even more diicult than that represented in Figs. 1, 2, and 3, and on a sufficient scale for the cornices of large buildlngs.

The nature of our discovery consists in corrugating or molding sheet metal by means of properly-shaped dies acting in succession upon different parts of the sheet, substantially in the manner and for the purposes herein specitied. One method of effecting this process is to procure a lower or female die, of wood, metal,

or any suitable material,whose cross-section is the same, or nearly so, as that desired tobe produced in sheet metal, (see B B 13,) and this die does not differ from those now in use. A set of upper dies, D D D, are then procured, whose acting surfaces, when properly arranged, shall constitute a single surface conforming in shape to that of one side of the c'orrugated sheet to be produced, and we usually intend to arrange them within a proper `framing, as e e e, so that they shall be free to move toward and away from the under die. These dies should be properly guided so as to match the lower die with precision when forced toward it.

In the machine represented in Fig. 7 the dies serve partially as guides for each other, the outer sides of the outer dies being keptiu place by part of the frame, and the sides ofthe dies which otherwise would touch beingkeptapart bysmall projections. (Notrepresentcdin the drawings.)

The acting surfaces of the sectional dies may make up a complete surface, as in Figs. 5 and 6, or there may be an interval between the sections, as in Figs. 4E and 7.

We usually intend to support these dies in some proper manner, as by the springsfff, and to apply some mechanism for lifting and forcingv them down-such as the springs and the wedges g g g. y

In. molding or corrugating sheet metal4 by our process the sheet or rsheets are to be laid loosely upon the lower or bed die, and thenl any one of the upper dies is forced down upon it until the metal takes its proper shape. This die is then held or left in that position, andthe next die in succession in the series is brought down and held, and thus in succession until the operation is finished. If a die at or near the center be brought down first, then the plan is to [work right and left from it. If one ofthe end dies be iirst brought down, then the work man must continue in succession die by die to the other end. The precise lines of` division of the sectional dies must depend to -a great extent upon the conguration of the corrugation and the thickness and rigidity of the metal, which will govern the judgment of the constructor. rllhe more frequent the divisions are (so lo-ng as there are not more than two dies for each separate wrinkle, member, or corrufgation) the easier will be the operation; but

in all ordinary cases it will bea safe rule to make one die for each decided member of a molding or each depression of a corrugation. The instances shown in the drawings, taken in connection with this specilicatiou, will serve as a sufficient guide for a skillful workman. In all the figures the metal being acted upon is represented at the letters m m m, and a simple inspection ofthe drawings shows that it is perfectly free to -creep in and conform to shape when acted upon by numerous sectional dies acting in a series, and that it is nipped,strained, and impeded wherever it is attempted to be molded according to the old plan, as in Figs.

l, 2, and 3.

We do not think that any explanation 'can show more clearly the advantages of our process,land the distinction between it and the old one can in no way be made more clear than by a simple inspection of the drawings. We intend to raise and lower the dies in any convenient manner by screws, levers, cams, pis tons or plungers of pumps or small steam-cyl inders,or otherwise,and sometimes to use them as rams acting by their own weight, when dropped, or being forced down. by blows lof hammers. We intend to guide these dies in any convenient manner, and to cause them to approach the lower bed in parallel lines or otherwise, as may be most convenient. We also intend at times to use a sectional lower die in connection with sectional upper dies acting in succession, as a convenient method of obtaining several distinct patterns from a comparatively small number of dies and for other purposes.

We claim as new and of our own invention- 'Ihemethod of corrugating or molding sheet metal by several dies acting in succes'siomsubstantiall y in the manner specified, upon a sheet resting upon a bed die or dies, so as to cause the metal to conform to shape, substantially in the manner herein described.

In testimony whereof we have hereunto subscribed our names, in the cityof New York, on this 24th day of February, A. D. 1858.

WV. E. VORTHEN- l HENRY B. RENVICK.

In presence of- R. S. GILLESPIE,

GHAs. WRIGHT. 

